/Engine/Source/Editor/UnrealEd/Public/ThumbnailExternalCache.h
Load thumbnails for the given object names from external cache
bool LoadThumbnailsFromExternalCache ( const [TSet](API\Runtime\Core\Containers\TSet)< [FName](API\Runtime\Core\UObject\FName) > & InObjectFullNames, FThumbnailMap & InOutThumbnails )